Telephone call-signal.



J. J. WETMORE.

TELEPHONE CALL SIGNAL.

APPLICATION FILED JUNE 10, 1914.

THE COLUMBIA PLANOGRAPH co., WASHINGTON. D c

Patented; May 9, 1916.

JOHN J'. WETMORE, OF SYRACUSE, NEW YORK.

TELEPHONE CALL-SIGN AL.

Specification of Letters Patent.

Patented May 9, 1916.

Application filed June 10, 1914. Serial No. 844,143.

To all whom it may concern Be it known that I, JOHN J. WETMORE, of Syracuse, in the county of Onondaga, in the State of New York, have invented new and useful Improvements in Telephone Call- Signals, of which the following, taken in connection with the accompanying drawings, is a full, clear, and exact description.

This invention relates to certain improvements in telephone call signal and refers more particularly to the retracting spring for the vibratory bell striker and adjusting means therefor.

The bell-operating mechanism including the electro-magnets, armature and striker rod and also the supporting frame for these parts together with portions of the wires leading to the magnets are usually located within a box having a door at the front which is normally locked and adapted to be opened only by an authorized representative of the telephone company to permit access to the interior for adjustment or repairs and usually the adjusting means is located back of the wires which are brought down in front of the magnets and prevent easy access to the adjusting means for the retracting spring for the vibratory striker so that, in some instances, it becomes necessary to detach some of the wires to make the necessary adjustments.

The main object is to enable the bell striker to be adjusted more closely and with greater ease, accuracy and reliability than has heretofore been practised by bringing the adjusting means some distance to the front of the magnets and wires leading thereto where it is always accessible when the door is opened without disturbing any of the leads or other parts of the bell-operating mechanism.

Another object is to reduce the liability of weakening of the retracting spring by using a plurality of comparatively light leaf springs instead of a coil spring.

Other objects and uses will be brought out in the following description.

In the drawings Figure 1 is a front elevation of a telephone-bell-ringing mechanism showing my improved adjustingmeans for the retracting spring for the bell striker. Fig. 2 is a side elevation of the same mechanism. Fig. 3 is an enlarged horizontal sectional view taken on the line 33, Fig. 2. Fig. 4 is a side elevation of the detached armature support showing the spring-supporting bracket integral therewith together with the spring and its adjusting means.

In order that my invention may be clearly understood, I have shown the usual telephone bells a a and electromagnets :b b as mounted upon a suitable supporting frame c having an armature support -cZ, the latter consisting of a cross bar or plate having central apertured lugs or ears e for receiving adjustable pivotal pins by which the rocking armature as g is centrally supported in prox- 1m1ty to the lower ends of the pole pieces of the magnets as shown more clearly in Fig. 1. This armature is provided with the usual vibratory bell striker h extending upwardly from the armature in a plane midway between the magnets and the bells a.

The particular feature of my invention consists in providing the armature support -d with a forwardly extending bracket 1 preferably integral therewith for receiving leaf springs -2 and an adjusting screw 3 therefor. These leaf springs 2- are made of comparatively light flat strips of spring metal and are secured at their front ends by suitable fastening means as screws 4 to the adjacent end of the bracket 1, the free portions thereof being bowed outwardly and extending rearwardly along one side of the bracket .1 so as to engage one side of the stem of the bell striker h to normally force said striker toward one of the bells or to one side of its medial line of vibration, said springs lying fiatwise one against the other.

The adjusting screw 3 is engaged in a threaded aperture in the front end of the bracket 1 just at the rear of the fastenlng screws 4 so as to engage the inner leaf for adjusting the free ends of said leaves in the direction of vibration of the bell striker for the purpose of varying the pressure with which the striker is retracted to its normal position, said spring being tensloned to spring toward the adjusting screw so that by turning the screw in one direction, the pressure of the spring upon the bell striker may be increased, while turning it in the opposite direction reduces such pressure.

It will be observed that the front ends of the springs together with the adjusting screws are located some distance in front of the plane of the electro-magnets and also in a plane substantially midway between said magnets to permit easy access thereto and especially to the adjusting screw for properly adjusting the springs -2- when the 7 door is opened without in any way interfer- Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents,

ture for the magnets, and a-bell striker on' the armature, of a frame having a bracket extendmg some dlstance to the front of and in a plane above the armature, a leaf spring having one end secured to the front end of k the bracket and its rear end engaged with the bell striker at a point between the armature and bells, and means on the bracket for adjusting the spring.

In witness whereof I have hereunto set my hand this 28th day of May 191 i.

JOHN J. WETMORE. Vitnesses:

H. E. CHASE, EVA E. GREENLEAF.

. Washington, D. G. 

